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Introduction: Occupational exposure data frequently include missing or incomplete measurements that, if not addressed, can result in an increased potential for exposure misclassification. Standard ...

Uranium is a ubiquitous metal that is nephrotoxic at high doses. Few epidemiologic studies have examined the kidney filtration impact of chronic environmental exposure. In 684 lead workers environmentally exposed to uranium, multiple linear regression was used to examine associations of uranium measured in a 4-h urine collection with measured creatinine clearance, serum creatinine- and cystatin-C-based estimated glomerular filtration rates, and N-acetyl-β-D-glucosaminidase (NAG). Three methods were utilized, in separate models, to adjust uranium levels for urine concentration--μg uranium/g creatinine; μg uranium/l and urine creatinine as separate covariates; and μg uranium/4 h. Median urine uranium levels were 0.07 μg/g creatinine and 0.02 μg/4 h and were highly correlated (rs=0.95). After adjustment, higher ln-urine uranium was associated with lower measured creatinine clearance and higher NAG in models that used urine creatinine to adjust for urine concentration but not in models that used total uranium excreted (μg/4 h). These results suggest that, in some instances, associations between urine toxicants and kidney outcomes may be statistical, due to the use of urine creatinine in both exposure and outcome metrics, rather than nephrotoxic. These findings support consideration of non-creatinine-based methods of adjustment for urine concentration in nephrotoxicant research.

Exposure to inorganic arsenic via drinking water is a growing public health concern. We conducted a systematic review of the literature examining the association between arsenic in drinking water and the risk of lung cancer in humans. Towards this aim, we searched electronic databases for articles published through April 2006. Nine ecological studies, two case–control studies, and six cohort studies were identified. The majority of the studies were conducted in areas of high arsenic exposure (100 μg/L) such as southwestern Taiwan, the Niigata Prefecture, Japan, and Northern Chile. Most of the studies reported markedly higher risks of lung cancer mortality or incidence in high arsenic areas compared to the general population or a low arsenic exposed reference group. The quality assessment showed that, among the studies identified, only four assessed arsenic exposure at the individual level. Further, only one of the ecological studies presented results adjusted for potential confounders other than age; of the cohort and case–control studies, only one-half adjusted for cigarette smoking status in the analysis. Despite these methodologic limitations, the consistent observation of strong, statistically significant associations from different study designs carried out in different regions provide support for a causal association between ingesting drinking water with high concentrations of arsenic and lung cancer. The lung cancer risk at lower exposure concentrations remains uncertain.

Asthma prevalence in the Cataño Air Basin of Puerto Rico is 27% for children aged 13-14 years and 45% for children aged 5-6 years. There is concern that these rates are related to air pollution. The authors conducted a nested case-control study to evaluate whether proximity to air pollution point sources was associated with increased risk of asthma attacks. For 1997-2001, 1,382 asthma-related medical visits (International Classification of Diseases, Ninth Revision, codes 493 and 493.9) in children under 17 were identified through health insurance claims. Controls were children with no asthma attacks who were randomly selected from enrollees in two health insurance companies by incidence density sampling (1:5) and matched to cases on gender, age, insurance company, and event date. The distance from a point source to the subject's residence area represented a surrogate exposure measurement. Odds ratios for a 1-km decrease in distance were obtained by conditional logistic regression. Risk of asthma attack was associated with residing near a grain mill (odds ratio (OR) = 1.35), petroleum refinery (OR = 1.44), asphalt plant (OR = 1.23), or power plant (OR = 1.28) (all p's0.05). Residence near major air emissions sources (100 tons/year) increased asthma attack risk by 108% (p0.05). These results showed that proximity to some air pollution sources is associated with increased risks of asthma attacks.

Objective To determine risk for incident basal cell carcinoma from cumulative low-dose ionising radiation in the US radiologic technologist cohort. Methods We analysed 65 719 Caucasian technologists who were cancer-free at baseline (1983–1989 or 1994–1998) and answered a follow-up questionnaire (2003–2005). Absorbed radiation dose to the skin in mGy for estimated cumulative occupational radiation exposure was reconstructed for each technologist based on badge dose measurements, questionnaire-derived work history and protection practices, and literature information. Radiation-associated risk was assessed using Poisson regression and included adjustment for several demographic, lifestyle, host and sun exposure factors. Results Cumulative mean absorbed skin dose (to head/neck/arms) was 55.8 mGy (range 0–1735 mGy). For lifetime cumulative dose, we did not observe an excess radiation-related risk (excess relative risk/Gy=−0.01 (95% CI −0.43 to 0.52). However, we observed that basal cell carcinoma risk was increased for radiation dose received before age 30 (excess relative risk/Gy=0.59, 95% CI −0.11 to 1.42) and before 1960 (excess relative risk/Gy=2.92, 95% CI 1.39 to 4.45). Conclusions Basal cell carcinoma risk was unrelated to low-dose radiation exposure among radiologic technologists. Because of uncertainties in dosimetry and sensitivity to model specifications, both our null results and our findings of excess risk for dose received before age 30 and exposure before 1960 should be interpreted with caution.

The U.S. Environmental Protection Agency (U.S. EPA) classifies dichloromethane (DCM) as a "probable human carcinogen," based upon its risk assessment conducted in the late 1980s (http://www.epa.gov/iris/subst/0070.htm). Since that time, cancer risk-assessment practices have evolved, leading to improved scientifically based methods for estimating risk and for illuminating as well as reducing residual uncertainties. A new physiologically based pharmacokinetic (PBPK) model has been developed, using data from human volunteers exposed to low DCM levels, that provides new information on the human to human variability in DCM metabolism and elimination (L. M. Sweeney et al., 2004, Toxicol. Lett. 154, 201-216). This information, along with data from other published human studies, has been used to develop a new cancer risk estimation model utilizing probabilistic methodology similar to that employed recently by U.S. EPA for other chemicals (ENVIRON Health Sciences Institute, 2005, Development of population cancer risk estimates for environmental exposure to dichloromethane using a physiologically based pharmacokinetic model. Final Report to Eastman Kodak Company). This article summarizes the deliberations of a scientific peer-review panel convened on 3 and 4 May 2005 at the CIIT Centers for Health Research in Research Triangle Park, North Carolina, to review the "state of the science" for DCM and to critically evaluate the new information for its utility in assessing potential human cancer risks from DCM exposure. The panel (Melvin E Andersen, CIIT Centers for Health Research, Research Triangle Park, NC 27709; A. John Bailer, Miami University, Scripps Gerontology Center, Oxford, OH 45056; Kenneth S. Crump, ENVIRON Health Sciences Institute, Ruston, LA 71270; Clifford R. Elcombe, University of Dundee, Biomedical Research Centre, Dundee DD1 9SY, United Kingdom; Linda S. Erdreich, Exponent, 420 Lexington Avenue, Suite 1740, New York, NY 10170; Jeffery W. Fisher, University of Georgia, Department of Environmental Health Science, Athens, GA 30602; David Gaylor, Gaylor and Associates, LLC, Eureka Springs, AR 72631; F Peter Guengerich, Vanderbilt University, Department of Biochemistry, Nashville, TN 37232; Kenneth Mundt, ENVIRON Health Sciences Institute, Amherst, MA 01004; Lorenz R Rhomberg, Gradient Corporation, Cambridge, MA 021138; Charles Timchalk, Pacific Northwest National Laboratory, Richland, WA 99352), chaired by M.E.A., was composed of experts in xenobiotic metabolism and carcinogenic mechanisms, PBPK modeling, epidemiology, biostatistics, and quantitative risk assessment. Observers included representatives from U.S. EPA, CIIT, and Eastman Kodak Company (Kodak), as well as several consultants to Kodak. The workshop was organized and sponsored by Kodak, which employs DCM as a solvent in the production of imaging materials. Overall, the panel concluded that the new models for DCM risk assessment were scientifically and technically sound and represented an advance over those employed in past assessments.

Background: Investigators from the Centers for Disease Control and Prevention (CDC), National Program of Cancer Registries (NPCR), are collaborating with public health professionals from seven states and the District of Columbia to conduct the Patterns of Care study to assess the quality of cancer data and to determine whether stage-specific treatments are being carried out. Methods: To assess the quality and completeness of cancer care data in the United States, trained staff from the Patterns of Care study are abstracting medical records to obtain detailed clinical data on treatment, tumor characteristics, stage at diagnosis, and demographics of representative samples of patients diagnosed with breast, colon, and prostate cancer. Altogether staff from each of the eight participating cancer registries will abstract 500 cases of breast, prostate, and colon/rectum/anus cancer for the CONCORD study and an additional 150 cases of localized breast cancer, 100 cases of stage III colon cancer, and 100 cases of localized prostate cancer for the Patterns of Care study. Chi-square tests will be used to compare routine registry data with re-abstracted data. The investigators will use logistic regression techniques to describe the characteristics of patients with localized breast and prostate cancer and stage III colon cancer. Age, race, sex, type of insurance, and comorbidity will be examined as predictors of the use of those treatments that are consistent with consensus guidelines. The investigators plan to use data from the CONCORD study to determine whether treatment factors are the reason for the reported differences between relative survival rates in the United States and Europe. Conclusions Results from the methodology used in the Patterns of Care study will provide, for the first time, detailed information about the quality and completeness of stage and treatment data that are routinely collected by states participating in the NPCR. It will add significantly to our understanding of factors that determine receipt of treatment in compliance with established guidelines. As part of the CONCORD study, it will also examine differences in survival among cancer patients with breast, prostate, and colon/rectum/anus cancers in the United States and Europe.

BACKGROUND Investigators from the Baltimore-Washington Infant Study (BWIS) reported an association between self-reported maternal lead exposure and total anomalous pulmonary venous return (TAPVR) in their offspring. This association was further evaluated in the BWIS population using a more sensitive exposure estimate. METHODS Cases included 54 live-born infants with TAPVR; controls were a stratified random sample of 522 live-born infants from the BWIS control group. Parental lead exposure was based on three assessment methods, including: an industrial hygiene assessment, an a priori job exposure matrix, and self-reported exposures. A parent was classified as exposed to lead if he/she was classified as exposed by any one of the assessment methods. RESULTS Approximately 17% of case mothers and 11% of control mothers were classified as exposed to lead during the three months prior to conception through the first trimester (odds ratio [OR], 1.57; 95% confidence interval [CI], 0.64–3.47). Among fathers, 61% of case fathers and 46% of control fathers were classified as exposed to lead during the six months prior to conception (paternal critical period) (OR, 1.83; 95% CI, 1.00–3.42). During the paternal critical period, when only the father was exposed compared to neither parent exposed, the OR for any lead exposure and TAPVR was 1.65 (95% CI, 0.84–3.25). CONCLUSIONS This study supports a possible association between paternal lead exposure and TAPVR. Further studies are warranted using validated assessment methods for occupational and nonoccupational lead exposures to corroborate this association and to elucidate the possible biological mechanism. Birth Defects Research (Part A), 2004. © 2004 Wiley-Liss, Inc.

Epidemiologic studies have consistently reported increased daily mortality and hospital admissions for ischemic heart disease related to daily changes in ambient particulate levels. One theory is that substances adhering to particulates might have a cardiovascular effect. Styrene has been found in very low doses in air and has chemical characteristics that would cause adherence to particles. Industrial studies have found an increase in cardiovascular disease among styrene-exposed workers. To explore a possible dose-response relation between styrene exposure and ischemic heart disease, the authors of this case-cohort study included 498 cases that died from ischemic heart disease and a 15% random sample (n = 997) of all male workers who were employed during 1943-1984 in two styrene-butadiene rubber-manufacturing plants in the United States. Proportional hazards models showed that recent styrene exposure was significantly associated with acute ischemic heart disease death among active workers. The relative hazard of death from acute ischemic heart disease for exposure during the most recent 2 years among active workers with 2 or more years of employment was 2.95 (95% confidence interval: 1.02, 8.57) at a time-weighted styrene concentration of 0.2

Data are limited on the role of chronic exposure to low-dose ionizing radiation in the etiology of cancer. In a nationwide cohort of 146,022 U.S. radiologic technologists (73% female), we evaluated mortality risks in relation to work characteristics. Standardized mortality ratios (SMRs) were computed to compare mortality in the total cohort vs. the general population of the United States. Mortality risks were low for all causes (SMR = 0.76) and for all cancers (SMR = 0.82) among the radiologic technologists. We also calculated relative risks (RR) for the 90,305 technologists who responded to a baseline mailed questionnaire, using Poisson regression models, adjusted for known risk factors. Risks were higher for all cancers (RR = 1.28, 95% confidence interval [CI] = 0.93–1.69) and breast cancer (RR = 2.92, 95% CI = 1.22–7.00) among radiologic technologists first employed prior to 1940 compared to those first employed in 1960 or later, and risks declined with more recent calendar year of first employment (p-trend = 0.04 and 0.002, respectively), irrespective of employment duration. Risk for the combined category of acute lymphocytic, acute myeloid and chronic myeloid leukemias was increased among those first employed prior to 1950 (RR = 1.64, 95% CI = 0.42–6.31) compared to those first employed in 1950 or later. Risks rose for breast cancer (p-trend = 0.018) and for acute lymphocytic, acute myeloid and chronic myeloid leukemias (p-trend = 0.05) with increasing duration of employment as a radiologic technologist prior to 1950. The elevated mortality risks for breast cancer and for the combined group of acute lymphocytic, acute myeloid and chronic myeloid leukemias are consistent with a radiation etiology given greater occupational exposures to ionizing radiation prior to 1950 than in more recent times. © 2002 Wiley-Liss, Inc.

We evaluated breast cancer mortality through 1997 among 69 525 female radiologic technologists who were certified in the United States from 1926 through 1982 and who responded to our questionnaire. Risk of breast cancer mortality was examined according to work history and practices and was adjusted for known risk factors. Breast cancer mortality risk was highest among women who were first employed as radiologic technologists prior to 1940 (relative risk [RR] = 2.92, 95% confidence interval [CI] = 1.22 to 7.00) compared with risk of those first employed in 1960 or later and declined with more recent calendar year of first employment (P for trend = .002). Breast cancer mortality risk increased with increasing number of years of employment as a technologist prior to 1950 (P for trend = .018). However, risk was not associated with the total number of years a woman worked as a technologist. Technologists who first performed fluoroscopy (RR = 1.69, 95% CI = 1.02 to 3.11) and multifilm procedures (RR = 1.87, 95% CI = 1.04 to 3.34) before 1950 had statistically significantly elevated risks compared with technologists who first performed these procedures in 1960 or later. The high risks of breast cancer mortality for women exposed to occupational radiation prior to 1950 and the subsequent decline in risk are consistent with the dramatic reduction in recommended radiation exposure limits over time.

Received for publication April 27, 2001, and accepted for publica-tion August 29, 2001.Abbreviations: ALARA, as low as reasonably achievable; BEIR,Biological Effects of Ionizing Radiation; ICRP, InternationalCommission on Radiation Protection; NCRP, National Council onRadiation Protection and Measurements; UNSCEAR, UnitedNations Scientific Committee on the Effects of Atomic Radiation.

PURPOSE: We evaluated an association between veterans' Gulf War service and reported adverse pregnancy outcomes. METHODS: We conducted a health survey in which selected reproductive outcomes of a population-based sample of 15,000 Gulf War veterans representing four military branches and three unit components (active, reserve, and National Guard) were compared to those of 15,000 non-Gulf veteran controls. RESULTS: Male Gulf veterans, compared with their non-Gulf veteran controls, reported a significantly higher rate of miscarriage (odds ratio [OR] = 1.62; 95% confidence interval [CI] = 1.32–1.99). Female Gulf veterans also reported more miscarriages than their respective controls, although their excess was not statistically significant (OR= 1.35; CI = 0.97–1.89). Both men and women deployed to the Gulf theater reported significant excesses of birth defects among their liveborn infants. These excess rates also extended to the subset of “moderate to severe” birth defects [males: OR= 1.78 (CI = 1.19–2.66); females: OR = 2.80 (CI = 1.26–6.25)]. No statistically significant differences by deployment status were found among men or women for stillbirths, pre-term deliveries or infant mortality. CONCLUSION: The risk of veterans reporting birth defects among their children was significantly associated with veteran's military service in the Gulf War. This observation needs to be confirmed by a review of medical records to rule out possible reporting bias.

Disinfection by-products (DBP) are a side effect of water chlorination. Some toxicological studies suggest an association between DBP exposure and adverse reproductive and developmental effects. This investigation considered all toxicological and epidemiological evidence for the various effects, outcome by outcome. The weight of evidence demonstrated that no association with DBP exposure exists for over a dozen outcomes including low and very low birth weight, preterm delivery, some specific congenital anomalies, and neonatal death. The analysis found inconsistent or very weak results for all congenital anomalies/birth defects, all central nervous system anomalies, neural tube defects, spontaneous abortion, and stillbirth. The weight of evidence suggested a positive association with DBP exposure for some measure of growth retardation (such as intrauterine growth retardation or small for gestational age) and for urinary tract anomalies. Having catalogued these effects, it should be noted that exposure assessment in the epidemiological studies published to date has been inadequate to definitively demonstrate an association of small magnitude. Exposure to DBP primarily has been based on routine (i.e., quarterly) monitoring of public water supplies for trihalomethanes (THM) matched to maternal residence. In order to determine whether an association exists between adverse reproductive and developmental effects and exposure to DBP, studies must consider the THM concentration and the quantity of the water actually consumed by pregnant women.

A population from a hearing clinic in Washington County, Maryland, in 1943-1960 was followed to assess the risk of developing neoplasms from radium treatment of the nasopharynx for adenoid hypertrophy. Of the 2,925 subjects who attended the clinic, 904 received radium treatment. A nonconcurrent prospective study compared the cancer incidence among the irradiated persons with that among persons with other treatments. Seven brain tumor cases (three malignant and four benign) were identified in the irradiated group versus none in the nonirradiated group (relative risk = 14.8, 95% confidence interval: 0.76, 286.3). A nonsignificant excess risk of thyroid cancer was detected in the irradiated group based on two cases in the exposed group and one case in the nonexposed group (relative risk = 4.2, 95% confidence interval: 0.38, 46.6). Decreased risks of breast cancer, female genital cancers, and prostate cancer were observed among the irradiated individuals, although these deficits were not statistically significant individually. The decreased risk of sex hormone-related cancers in the irradiated group suggests possible radiation damage to the pituitary, with consequent reduction in pituitary hormone output and alterations in sexual and other hormonal development in early life. This hypothesis needs further evaluation.

We thank Dr Kawada1 for his interest in our manuscript entitled ‘Associations of Multiple Metals with Kidney Outcomes in Lead Workers.’2 As clearly stated in the methods, diabetes and hypertension diagnoses (based on participant report of …

Background Since the 1965–1975 Vietnam War, there has been persistent concern that women who served in the U.S. military in Vietnam may have experienced adverse pregnancy outcomes. Methods We compared self-reported pregnancy outcomes for 4,140 women Vietnam veterans with those of 4,140 contemporary women veterans who were not deployed to Vietnam. As a measure of association, we calculated odds ratios (OR) and 95% confidence intervals (CI) using logistic regression adjusting for age at conception, race, education, military nursing status, smoking, drinking and other exposures during pregnancy. Results There was no statistically significant association between military service in Vietnam and index pregnancies resulting in miscarriage or stillbirth, low birth weight, pre-term delivery, or infant death. The risk of having children with “moderate-to-severe” birth defects was significantly elevated among Vietnam veterans (adjusted OR = 1.46, 95% CI = 1.06–2.02). Conclusions The risk of birth defects among index children was significantly associated with mother's military service in Vietnam. Am. J. Ind. Med. 38:447–454, 2000. Published 2000 Wiley-Liss, Inc.

A study of pulp and paper mill workers indicated low risks of death from all causes (standardized mortality ratio (SMR)5 0.74) and all cancers (SMR5 0.81) compared with U.S. rates. The leukemia death rate in workers was not higher than the U.S. rate but was higher than the rate in county populations surrounding mills. Workers whose last jobs were in the finishing areas of the mills had an elevated SMR for liver cancer. An internal comparison of occupational characteristics indicated that workers employed in mills using other chemical pulping operations had significantly elevated mortality from all causes, all cancers, heart disease, lymphomas, and brain cancers. Lung cancer mortality was elevated in mills using kraft pulping. The internal comparisons confirmed the association between work in finishing and the risk of liver cancer. This study was designed to investigate whether pulp and paper mill workers have any risks that would indicate the need for studies detailing exposures. Am. J. Ind. Med. 33:354‐365, 1998. r 1998 Wiley-Liss, Inc.

Workers in abattoirs and meatpacking plants have potential for exposure to bovine leukemia virus (BLV) and bovine papilloma viruses (BPV), which are oncogenic in cattle. These workers also have increased exposure to human papilloma viruses (HPV) and certain chemical carcinogens. We investigated whether such a group showed increased risk of cancers. We report mortality results after an additional 9-year follow-up of a previously studied group of 5,522 workers in abattoirs and 4,589 workers in meatpacking plants. Excess risk of all cancers combined, cancers of the lung, buccal cavity and pharynx, esophagus, colon, bladder, kidney, and bone was observed. Since factors such as tobacco smoking, alcohol, and diet, which have known associations with some of these cancers, were not taken into account, the significance of these findings is not known, except for lung cancer, for which occupational factors are probably involved. Because some of these findings have been consistently reported before, studies that will control for confounding factors as well are now urgently needed.

Objectives Environmental exposure to multiple metals is common. A number of metals cause nephrotoxicity with acute and/or chronic exposure. However, few epidemiologic studies have examined the impact of metal coexposure on kidney function. Therefore, the authors evaluated associations of antimony and thallium with kidney outcomes and assessed the impact of cadmium exposure on those associations in lead workers. Methods Multiple linear regression was used to examine associations between ln-urine thallium, antimony and cadmium levels with serum creatinine- and cystatin-C-based glomerular filtration measures and ln-urine N-acetyl-β-D-glucosaminidase (NAG). Results In 684 participants, median urine thallium and antimony were 0.39 and 0.36 μg/g creatinine, respectively. After adjustment for lead dose, urine creatinine and kidney risk factors, higher ln-urine thallium was associated with higher serum creatinine- and cystatin-C-based estimates of glomerular filtration rate; associations remained significant after adjustment for antimony and cadmium (regression coefficient for serum creatinine-based estimates of glomerular filtration rate =5.2 ml/min/1.73 m 2 ; 95% CI =2.4 to 8.0). Antimony associations with kidney outcomes were attenuated by thallium and cadmium adjustment; thallium and antimony associations with NAG were attenuated by cadmium. Conclusions Urine thallium levels were significantly associated with both serum creatinine- and cystatin-C-based glomerular filtration measures in a direction opposite that expected with nephrotoxicity. Given similarities to associations recently observed with cadmium, these results suggest that interpretation of urine metal values, at exposure levels currently present in the environment, may be more complex than previously appreciated. These results also support multiple metal analysis approaches to decrease the potential for inaccurate risk conclusions.

The purpose of this paper is to present the assessment of magnetic field exposure conducted as a part of a nested case-control investigation of leukemia mortality in telephone lineworkers. For the purposes of exposure classification, telephone company jobs were initially divided into two classes: those with potential for working in an electric environment, referred to as linework jobs, and those not working in an electric environment, referred to as nonlinework jobs. Linework jobs were further divided into the following four categories: outside plant technicians (OPT), installation/maintenance/repair (IMR) technicians, central office technicians (COT), and cable splicing technicians (CST). These job groupings were based on similarity of work tasks and exposure environments. Emdex data-logging dosimeters were used to measure personal exposures to ELF magnetic fields for 204 telephone company workers. Three general classes of exposure indices were calculated for each exposure record: measures of central tendency, measures of peak or maximum exposure, and measures of exposure variability. CSTs had the highest full-shift mean and median exposure, 4.3 and 3.2 mG, respectively. CSTs also ranked the highest, with average peak, average 95th percentile, and average time above background equal to 99.2 mG, 11.1 mG, and 156 min, respectively. In addition, the results suggest the OPT and IMR technicians have exposures similar to nonlineworkers. Exposure classifications, therefore, which misclassify all lineworkers into one “telephone lineworker” job grouping are not appropriate and future studies should concentrate on cable splicing technicians.

A clinic-based case-control study was conducted to determine the association between vitamin supplement use and risk of basal cell carcinoma (BCC) of the skin. The subjects were 131 patients with histopathologically confirmed primary BCC and 200 cancer-free controls with non-premalignant skin disorders. Use of any vitamins (mainly multivitamins and vitamins A, C, and E) was associated with reduced risk of BCC. After controlling for age, sex, cigarette smoking, number of lifetime severe sunburns, and skin actinic elastosis, regular vitamin supplementation was associated with a significantly reduced risk of BCC (odds ratio (OR) = 0.3; 95% confidence interval (CI) = 0.2-0.06). The ORs decreased as the regularity (p < 0.001) and daily doses of supplement used increased, especially for vitamins A (p < 0.005) and E (p < 0.005). Vitamin supplementation was not associated with alterations in cellular DNA repair. These results, however, cannot be considered conclusive because of the relatively low participation rates (131/830 for cases and 200/1406 for controls) due to the requirement of blood donation and more rigorous studies are needed to clarify the effect of supplemental vitamins, particularly of vitamins A and E, on the risk of BCC of the skin.

This case-control study examines potential associations between telephone linework and the occurrence of leukemia except chronic lymphocytic leukemia in a primarily retired population of American Telephone and Telegraph Company (AT&T) workers. Cases died between 1975 and 1980. Exposure is defined both by job title and, for workers with complete job histories, by a lifetime exposure score based on industrial hygiene personal monitoring measurements of line and nonline jobs. When the time-weighted average mean for each job is accumulated into a lifetime exposure score, workers with scores above the median for the population show an excess of leukemia 2.5 times higher than workers below the median (95% confidence interval (CI) 0.7-8.6). Those individuals with long duration of employment in jobs with intermittent peak exposures may be at higher risk of leukemia than those with a constant exposure level. Analyses that allow for a latent period suggest the risk is associated with exposures that occurred 10 or more years before death. Workers with peak exposure scores above the median have odds ratios of 2.4 (95% CI 0.7-9.0) and 6.6 (95% CI 0.7-58) for latent periods of 10 and 15 years, respectively. The data suggest an increasing risk with increasing exposure (p for trend = 0.05) when cumulated scores are based on peak exposure scores. Peak exposures tended to occur in cable splicing work and in old telephone switching offices. The numbers in this study are small and observed differences may be due to chance.

This molecular epidemiology study examines the DNA-repair capacities (DRCs) of basal cell carcinoma (BCC) skin cancer patients (88) and their controls (135) by using a plasmid/host-cell reactivation assay. In this assay UV-damaged expression vector plasmid is transfected into peripheral blood T lymphocytes from the subjects. The host-cellular repair enzymes repair the photochemical damage in the plasmid, and 40 hr later the plasmid-encoded reporter chloramphenicol acetyltransferase is measured. An age-related decline in this DRC, amounting to approximately 0.61% per yr occurred in the controls from 20 to 60 yr of age. Reduced DRC was a particularly important risk factor for young individuals with BCC and for those individuals with a family history of skin cancer. Young individuals with BCC repaired DNA damage poorly when compared with controls. As the BCC patients aged, however, differences between cases and controls gradually disappeared. The normal decline in DNA repair with increased age may account for the increased risk of skin cancer that begins in middle age, suggesting that the occurrence of skin cancer in the young may represent precocious aging. Patients with reduced DRCs and overexposure to sunlight had an estimated risk of BCC > 5-fold greater than the control group. Such a risk was even greater (10-fold) in female subjects.

The authors investigated the effect of charcoal smoke exposure on risks of acute upper and lower respiratory infection (AURI and ALRI) among children under age 18 months in Santo Domingo, Dominican Republic (1991-1992). Children living in households using charcoal for cooking (exposed, n = 201) were age-matched to children living in households using propane gas (nonexposed, n = 214) and were followed for 1 year or until 2 years of age. Fuel use and new episodes of AURI and ALRI were ascertained biweekly through interviews and medical examinations. Household indoor-air concentration of respirable particulate matter (RPM) was measured in a sample of follow-up visits. Incidences of AURI and ALRI were 4.4 and 1.4 episodes/child-year, respectively. After adjustment for other risk factors, exposed children had no significant increase in risk of AURI but were 1.56 times (95% confidence interval: 1.23, 1.97) more likely to develop ALRI. RPM concentrations were higher in charcoal-using households (27.9 microg/m(3) vs. 17.6 microg/m(3)), and ALRI risk increased with RPM exposure (10-microg/m(3) increment: odds ratio = 1.17, 95% confidence interval: 1.02, 1.34). Exposure to charcoal smoke increases the risk of ALRI in young children, an effect that is probably mediated by RPM. Reducing charcoal smoke exposure may lower the burden of ALRI among children in this population.

Community interventions are increasingly recognized as an effective method for reaching individuals in need of health behavior change. We present our experience in developing and implementing an intervention to increase Pap test screening in an inner-city community with a high rate of cervical cancer mortality. Results of a baseline needs assessment survey showed that: almost one-half of the population was inadequately screened; 66 percent of inadequately screened women reported belonging to a church; and, a significant proportion of those who tended to rely on the physician for screening did not receive adequate testing. These results formed the basis of our community intervention strategy: lay peer educators, recruited predominantly from churches, were trained to motivate inadequately screened women to actively seek testing. The implementation of the intervention was flexible and responsive to insights gained in the field and process evaluation data. Recommendations for future community-based interventions are offered.

The association between weight, physical activity, and stress and variation in the length of the menstrual cycle was prospectively examined in 166 college women, aged 17-19 years, who kept menstrual diaries during their freshman year. The unadjusted probability of a menstrual cycle being longer than 43 days was 5%. Women with a history of long cycles were more likely to have a long cycle during the study (odds ratio (OR) = 4.3). Stressors, characterized by situations which create a demand for performance or require adjustments to new demands, also increased the risk of a long cycle. Odds ratios for gain events and for coping with multiple performance demands (2 vs. 0) were 1.9. Starting college increased the risk of long cycles (OR = 2.3) regardless of whether a woman had left home. Moderate exercise minimally increased the probability of a long cycle (OR = 1.1, 75th vs. 50th percentiles). Change in weight (OR = 1.9) and being overweight (OR = 1.2, 15% above standard weight for height) were independently associated with the probability of long cycles. When 17- to 43-day cycles were evaluated, a history of long cycles lengthened expected cycle length by 1.42 days, while dieting, living on campus, and starting college tended to shorten expected length by 1.38, 0.90, and 0.64 days, respectively. Further investigation of the biologic mechanisms that mediate the stress effect is warranted.

This study evaluated risk factors for injurious and noninjurious slips, trips, and falls among painters and investigated the hypothesis that exposure to solvents influenced the risk of such accidents. The data were collected longitudinally over an 11 month period. Weekly self-administered questionnaires detailed paint solvent exposure; work-related slips, trips, and falls (STFs); and potentially hazardous job tasks and environmental conditions. An initial questionnaire ascertained personal data, such as age, solvent exposure history, and alcohol consumption. During the study, 2,088 person-weeks of data were collected. Some participants provided many weeks of data, while others responded sporadically. Exposure to potentially hazardous environmental conditions was significantly related to the occurrence of STFs during a week. Several measures of solvent exposure were evaluated for their effect on STFs. Low solvent exposure during a week significantly increased the occurrence of slips, trips, and falls compared to no exposure. Moderate and high weekly exposure were not associated with increased risk, however. Week-to-week variability in the amount of solvent exposure was a strong positive predictor of STFs. Further analysis showed that both increases and decreases in solvent exposure between the preceding 2 weeks and the week of the STF were positively related to the risk of such events. The strongest effect was observed for exposure increases over the preceding 2 weeks. Overall, the results suggest that solvent exposure variability may increase accident risk, and possible explanations are explored. Language: en

BACKGROUND. Vaginal cancer is a rare malignancy. It has many of the same risk factors as cervical cancer, including a strong association with persistent human papillomavirus infection. Descriptive studies of the epidemiology of vaginal cancer are scarce in the literature. METHODS. The 1998 through 2003 incidence data from 39 population-based cancer registries were used, covering up to 83% of the US population. The 1996 through 2003 data from 17 cancer registries were used for survival analysis. Incidence rates, disease stage, and 5-year relative survival rates were calculated by race, ethnicity, and age group. Data analysis focused mainly on squamous cell carcinoma (SCC). RESULTS. Incidence rates for all vaginal cancers combined were 0.18 per 100,000 female population for in situ cases and 0.69 for invasive cases. The median age of invasive cases was older than that of in situ cases (aged 68 years vs 58 years). SCC was the most common histologic type (71% of in situ cases and 66% of invasive cases). Compared with the rate for white women, the age-adjusted incidence rate of invasive SCC was 72% higher (P < .05) among black women, whereas the rate among Asian/Pacific Islander (API) women was 34% lower (P < .05). Hispanic women had a 38% higher rate than non-Hispanic women (P < .05) of invasive SCC. The rates for in situ SCC peaked at age 70 years and then declined, whereas the rates of invasive SCC increased continuously with advancing age. Black, API, and Hispanic women as well as older women were more likely to be diagnosed with late-stage disease, and these groups had lower 5-year relative survival rates than their white, non-Hispanic, and younger counterparts. CONCLUSIONS. Incidence rates of vaginal SCC varied significantly by race, ethnicity, and age group. Black, API, and Hispanic women as well as older women had a high proportion of late-stage disease and a low 5-year survival rate. Cancer 2008;113(10 suppl):2873–82. Published 2008 by the American Cancer Society.

BACKGROUND Carotenoids are thought to have anti-cancer properties, but findings from population-based research have been inconsistent. OBJECTIVE We aimed to conduct a systematic review of the associations between carotenoids and lung cancer. DESIGN We searched electronic databases for articles published through September 2007. Six randomized clinical trials examining the efficacy of beta-carotene supplements and 25 prospective observational studies assessing the associations between carotenoids and lung cancer were analyzed by using random-effects meta-analysis. RESULTS The pooled relative risk (RR) for the studies comparing beta-carotene supplements with placebo was 1.10 (95% confidence limits: 0.89, 1.36; P = 0.39). Among the observational studies that adjusted for smoking, the pooled RRs comparing highest and lowest categories of total carotenoid intake and of total carotenoid serum concentrations were 0.79 (0.71, 0.87; P < 0.001) and 0.70 (0.44, 1.11; P = 0.14), respectively. For beta-carotene, highest compared with lowest pooled RRs were 0.92 (0.83, 1.01; P = 0.09) for dietary intake and 0.84 (0.66, 1.07; P = 0.15) for serum concentrations. For other carotenoids, the RRs comparing highest and lowest categories of intake ranged from 0.80 for beta-cryptoxanthin to 0.89 for alpha-carotene and lutein-zeaxanthin; for serum concentrations, the RRs ranged from 0.71 for lycopene to 0.95 for lutein-zeaxanthin. CONCLUSIONS beta-Carotene supplementation is not associated with a decrease in the risk of developing lung cancer. Findings from prospective cohort studies suggest inverse associations between carotenoids and lung cancer; however, the decreases in risk are generally small and not statistically significant. These inverse associations may be the result of carotenoid measurements' function as a marker of a healthier lifestyle (higher fruit and vegetable consumption) or of residual confounding by smoking.

It has long been known that the risks of some cancers, including endometrial, are associated with obesity. Recent evidence suggests that body fat distribution patterns also affect the risk of developing some diseases. A question that remains is whether cancers are associated with specific distributions of body fat. In this study, women with endometrial cancer were compared to community controls of similar age and race. Participants were interviewed and then measured to determine fat distribution patterns defined by the waist-to-hip circumference ratio. Women with upper body fat distribution had a 3.2-fold (95% confidence limits 1.2, 8.9) higher risk of endometrial cancer than women with lower body fat distribution even with correction for age, parity, and smoking. Obese women with an upper body fat pattern had a 5.8-fold (confidence limits 1.7, 19.9) higher risk of endometrial cancer than nonobese/lower body fat patterned women. Obese women who never smoked had a 3.3-fold statistically significant higher risk of endometrial cancer than nonobese women who never smoked. Current smokers had lower risks than their nonsmoking counterparts. The 3-fold increased risk of endometrial cancer associated with upper body fat did not disappear with adjustment for obesity and smoking.

This study investigated the relationships between health care utilization, knowledge, attitudes, sociodemographic characteristics, and adequacy of cervical cancer screening among a random sample of women from inner-city neighborhoods with high rates of cervical cancer mortality. Of 416 women interviewed, 30.3% reported hysterectomies; women with intact uteri (N = 290) are the subjects of this analysis. Over two-fifths (44.1%) reported not receiving adequate Pap testing during the previous 4 years. Compared with adequately screened women, they were more likely to be 45 years or older, have no medical insurance, report never having been to an obstetrician-gynecologist, recall never having been told by a medical provider how often to get a Pap test, rely on providers for adequate screening, report not seeking care as often as they think they should, have less knowledge of risk factors for cervical cancer, and believe that women should get Pap tests less than yearly. Separate models for younger and older women showed that these factors vary by age, demonstrating the need for interventions to be sensitive to age subgroups. These findings suggest that cancer control activities should place more emphasis on motivating women as well as influencing the health care delivery system to maximize reductions in cervical cancer.

The risks for four cancers, leukemia, lymphopoietic cancers (LHC), lung cancer and mesothelioma, were studied in workers from shipyards involved in nuclear powered ship overhauls. The population represented a sample of all workers based on radiation dose at study termination. The final sample included 28,000 workers with > or = 5.0 mSv, 10,462 workers with < 5.0 mSv and 33,353 non-nuclear workers. Nuclear workers had lower mortality rates for leukemia and LHC than US white males but higher rates of lung cancer and a significant five-fold excess of mesothelioma. Dose-dependent analyses of risks in the high exposure group indicated that for each cancer the risk increased at exposures above 10.0 mSv. An internal comparison of workers with 50.0 mSv exposures to workers with exposures of 5.0-9.9 mSv indicated relative risks for leukemia of 2.41 (95% CI: 0.5, 23.8), for LHC, 2.94 (95% CI: 1.0,12.0), for lung cancer, 1.26 (95% CI: 0.9, 1.9) and for mesothelioma, 1.61 (95% CI: 0.4, 9.7) for the higher exposure group. Except for LHC, these risks are not significant. However, the increasing risk with increasing exposure for these cancers, some of which are known to be related to radiation, suggests that low-level protracted exposures to gamma rays may be associated with these cancers. Other agents such as asbestos, which are common to shipyard work, may play a role especially in the risk of mesothelioma. Future follow up of the population would identify bounds on radiation risks for this population for comparison with similar risks estimated from other populations.

Background U.S. Army Chemical Corps veterans handled and sprayed herbicides in Vietnam resulting in exposure to Agent Orange and its contaminant 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin). This study examined the long-term health effects associated with herbicide exposure among these Vietnam veterans. Methods A health survey of these 1,499 Vietnam veterans and a group of 1,428 non-Vietnam veterans assigned to chemical operations jobs was conducted using a computer-assisted telephone interview (CATI) system. Exposure to herbicides was assessed by analyzing serum specimens from a sample of 897 veterans fordioxin. Logistic regressionanalyseswereusedtoestimatetheriskofselectedmedicaloutcomesassociated with herbicide exposure. Results Odds ratios for diabetes, heart disease, hypertension, and chronic respiratory disease were elevated, but not significantly (P>0.05) for those who served in Vietnam. However, they were significantly elevated among those Vietnam veterans who sprayed herbicides: diabetes, odds ratio (OR)" 1.50 (95% confidence interval [95%CI]" 1.15‐1.95); heart disease, OR" 1.52 (1.18‐1.94); hypertension, OR" 1.32 (1.08‐1.61); and chronic respiratory condition, OR" 1.62 (1.28‐2.05). Hepatitis was associated with Vietnam service, but not with herbicide application. Conclusions Vietnam veterans who were occupationally exposed to herbicide experienced a higher risk of several chronic medical conditions relative to other nonVietnam veterans. A potential selection bias is of concern. However, there were relativelyhighparticipationratesinboththeVietnamandnon-Vietnamveterangroups, and the prevalence rates of some of these medical conditions among non-Vietnam veterans were comparable to general populations. Therefore, self-selection factors are considered unlikely to have biased the study results. Am. J. Ind. Med.

BACKGROUND. Descriptions of population characteristics for intestinal cancers frequently combine colon and rectal sites. However, some studies suggest that cancers of subsites in the intestinal tract may differ both by demographics and biology. Examination of colon and rectal cancers' characteristics separately could identify different risk profiles for these sites. METHODS. Data from combined National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology, and End Results (SEER) databases were examined for risk characteristics by age, race, sex, and ethnicity, as well as for SEER-reported trends over 27 years. RESULTS. Males had higher incidences of both colon and rectal cancers, but this predominance was greater for rectal cancers. Colon cancer rates were higher for blacks than for whites but rectal cancer rates were slightly higher for whites than for blacks. The change in incidence rates by race occurred abruptly at sites in the lower colon. Asians had low rates of colon cancer, but their rectal cancer rates were similar to those of blacks. Trends for both sites showed declines in incidence rates in whites, but slight to no change in blacks. Mortality in blacks increased until about 10 years ago. CONCLUSIONS. Colon and rectal cancer sites should be studied independently because of major differences in their characteristics. Age-specific incidence rates differ by race and site. Any effect from screening is difficult to demonstrate because of changes in procedures over time, resulting in different levels of effective detection in the intestinal tract, and because of slow acceptance of screening by the public. Cancer 2006. © 2006 American Cancer Society.

The incidence rates of nasopharyngeal carcinoma (NPC) are dramatically higher in certain regions of Asia compared to the rest of the world. Few risk factors for NPC are known; however, in contrast to the hypothesized health benefits of nonpreserved vegetables, it is thought that preserved vegetable intake may play a role in contributing to the higher incidence of NPC in high-risk regions. Therefore, the purpose of this study was to systematically review the epidemiologic evidence on the associations between adulthood intake of preserved and nonpreserved vegetables and NPC risk. A search of the epidemiological literature from 1966 to 2004 was performed using several bibliographic databases, including PubMed and the Chinese Biomedical Literature Database System. There were no language restrictions. Meta-analysis was conducted to obtain pooled odds ratios (ORs) for the highest-versus-lowest categories of preserved and nonpreserved vegetable intake. A total of 16 case-control studies were identified in the search. Results showed that highest-versus-lowest preserved vegetable intake was associated with a 2-fold increase in the risk of NPC (Random Effects Odds Ratio (RE OR) 2.04; 95% Confidence Limits (CL) 1.43, 2.92). Conversely, high nonpreserved vegetable intake was associated with 36% decrease in the risk of NPC (RE OR 0.64; 95% CL 0.48, 0.85). Findings for both preserved and nonpreserved vegetables were consistent across vegetable type and by country of study. Further research in high-risk areas to gain insight into the risk associated with preserved vegetables and protection associated with nonpreserved vegetables may advance understanding of NPC and yield clues for prevention.

There is significant public concern about the potential health effects of exposure to mercury vapour (Hg(0)) released from dental amalgam restorations. The purpose of this article is to provide information about the toxicokinetics of Hg(0), evaluate the findings from the recent scientific and medical literature, and identify research gaps that when filled may definitively support or refute the hypothesis that dental amalgam causes adverse health effects. Dental amalgam is a widely used restorative dental material that was introduced over 150 years ago. Most standard dental amalgam formulations contain approximately 50% elemental mercury. Experimental evidence consistently demonstrates that Hg(0) is released from dental amalgam restorations and is absorbed by the human body. Numerous studies report positive correlations between the number of dental amalgam restorations or surfaces and urine mercury concentrations in non-occupationally exposed individuals. Although of public concern, it is currently unclear what adverse health effects are caused by the levels of Hg(0) released from this restoration material. Historically, studies of occupationally exposed individuals have provided consistent information about the relationship between exposure to Hg(0) and adverse effects reflecting both nervous system and renal dysfunction. Workers are usually exposed to substantially higher Hg(0) levels than individuals with dental amalgam restorations and are typically exposed 8 hours per day for 20-30 years, whereas persons with dental amalgam restorations are exposed 24 hours per day over some portion of a lifetime. This review has uncovered no convincing evidence pointing to any adverse health effects that are attributable to dental amalgam restorations besides hypersensitivity in some individuals.

Epidemiologic studies have consistently reported increased daily mortality and hospital admissions for ischemic heart disease related to daily changes in ambient particulate levels. One theory is that substances adhering to particulates might have a cardiovascular effect. Styrene has been found in very low doses in air and has chemical characteristics that would cause adherence to particles. Industrial studies have found an increase in cardiovascular disease among styrene-exposed workers. To explore a possible dose-response relation between styrene exposure and ischemic heart disease, the authors of this case-cohort study included 498 cases that died from ischemic heart disease and a 15% random sample (n = 997) of all male workers who were employed during 1943-1984 in two styrene-butadiene rubber-manufacturing plants in the United States. Proportional hazards models showed that recent styrene exposure was significantly associated with acute ischemic heart disease death among active workers. The relative hazard of death from acute ischemic heart disease for exposure during the most recent 2 years among active workers with 2 or more years of employment was 2.95 (95% confidence interval: 1.02, 8.57) at a time-weighted styrene concentration of 0.2-0.3 ppm and 4.30 (95% confidence interval: 1.56, 11.84) ator=0.3 ppm for the same exposure period, respectively.

Cancer of the uterine cervix, the sixth most common cancer among women, is still considered a significant health problem, despite declining mortality rates during recent decades. In Baltimore, the age-adjusted mortality rates for cervical cancer are significantly higher than the U.S. average, for both black and white women. Early detection of cervical cancer through screening with the Papanicolaou (Pap) test has been shown to decrease mortality by preventing development of invasive disease, and intervention programs have been developed to increase use of Pap testing. However, the evaluation of those programs is difficult, as self-reports of Pap screening may be inaccurate, and repeated inquiries about Pap tests may influence the behavior being studied. We report in this article a method to use data from cytopathology laboratories to estimate the use of Pap screening by women in a defined population. This approach can be used to evaluate changes in receipt of Pap smears and to provide feedback to intervention programs. [Am J Prev Med 1994;10:235–7]

Recent epidemiologic studies have consistently reported increased daily mortalities and hospital admissions associated with exposure to particulate air pollution. Ischemic heart disease (IHD*, International Classification of Diseases, Eighth Revision [ICD-8], codes 410-414) is among those diseases that contribute in large measure to this excess mortality. Some occupational studies have suggested elevated risk of IHD among workers exposed for short periods to styrene, which can be emitted from fossil fuel combustion, aircraft exhausts, and motor vehicle exhausts. Styrene is found in ambient air at average concentrations of a few micrograms per cubic meter or less but may reach very high concentrations at particular locations and times. Unmeasured aerosols of styrene may also increase population exposures. This case-cohort study explored a possible association and dose-response relation between styrene exposure and risk of acute IHD in an occupational setting. The population under study was 6587 male workers employed between 1943 and 1982 in two US plants manufacturing styrene-butadiene polymers used in synthetic rubber. The study assessed all 498 subjects who died from IHD along with a subcohort of twice that size, 997 subjects, selected as a 15% random sample of the full target cohort. IHD deaths during the study led to some overlap between cases and the subcohort, leaving 1424 unique subjects. Job histories were collected for all subjects. Industrial hygienists and engineers from the industry estimated relative exposures for all jobs. Exposure data were collected for many of the jobs from different sources. For any job with no available exposure measurements, z scores were used to estimate job exposure in each plant from the relative exposure level for that job in similar plants and the measurement distribution parameters of the study plant. Standardized mortality ratio (SMR) analyses were used to examine the overall risk of dying from IHD among study subjects compared with the US general population. A significantly elevated SMR of 1.47 with a 95% confidence interval (95% CI) of 1.17 to 1.77 for chronic IHD was found among black workers who had left the plants. A modification of the Cox proportional hazard regression model was used to control for confounders and examine dose-response relations between styrene exposure and the risk of IHD. Employment time-weighted average (TWA) styrene concentration intensity for the most recent 2 years was found significantly associated with death from acute IHD among active workers with a relative hazard of 3.26 to 6.60, depending on duration of employment. In this analysis, the highest relative hazard of 6.60 (95% CI, 1.78-24.54) was among active workers who had been employed for at least 5 years. The results suggest that the exposure intensity was more important than duration of exposure. On the basis of the dose-response relation established in this study, we estimate that for each 10 microg/m3 increase in ambient styrene, acute IHD mortality might increase 0.4%. At normal ambient styrene levels, the relative risk would be increased, at most, 0.1% compared with no exposure. At certain locations and times, however, ambient styrene could reach levels that would result in a relative hazard for acute IHD mortality as high as 3.386-fold the risk at no exposure.

The long-term health consequences of exposure to phenoxyherbicides used in Vietnam has been a great concern to the veterans. In addition to the Air Force Ranch Hand personnel, Army Chemical Corps personnel who served in Vietnam are thought to have had some of the highest herbicide exposures. The Department of Veterans Affairs commenced a study of veterans who served in Vietnam as members of the Army Chemical Corps and a comparison cohort of Army Chemical Corps personnel who served elsewhere. A total of 2872 Vietnam veterans and 2737 non-Vietnam veterans who served in the Army Chemical Corps were identified for inclusion in a telephone health interview survey with a random 20% sample of veterans receiving serum dioxin and other congeners assessments. In a feasibility study which included 284 Vietnam veterans and 281 non-Vietnam veterans, 100 serum assessments were conducted of which 95 were included in the analysis. Vietnam veterans with a history of spraying herbicides were found to have a statistically significant elevation in their current serum 2,3,7,8-TCDD concentrations compared to non-Vietnam veterans without a spray history (P = 0.05). Other 2,3,7,8-substituted dioxins levels were comparable to the levels found in the non-Vietnam veterans. This feasibility study demonstrated that serum dioxin concentrations from a sample of the study participants can be used to identify exposure variables in the health survey that can serve as a surrogate measure of phenoxyherbicide exposure.

Time trends in employee exposures to the air contaminants measured by the Occupational Safety and Health Administration (OSHA) during compliance inspections of pulp and paper manufacturing facilities conducted between 1979 and 1997 were evaluated based on the measurement results stored in the OSHA Integrated Management Information System (IMIS) database. The IMIS database is among the largest sources of occupational exposure measurements available for occupational health research in the United States. The IMIS database contains the results of 3,568 personal time-weighted average (TWA) measurements for 171 air contaminants made at 524 establishments in Standard Industrial Classification (SIC) 26. An analysis of these measurements revealed an overall decrease in the total number of measurements made per year since 1991, and a decrease in the percentage of measurements by year that exceeded the OSHA permissible exposure limits (PELs). Linear regression analyses detected decreasing trends in the geometric mean concentrations by year for 33 of the 36 agents analyzed.

Drinking mutagenic downstream water from the Huangpu River was hypothesized to have increased the risk for male esophageal cancer in Shanghai, China. The authors conducted a population-based case-control study of a total of 71 esophageal cancer deaths and 1,122 controls collected during a 5-year follow-up period, 1984-1988, from four male cohorts born before January 1, 1944, living in four communities consuming water with different mutagenicities in the Shanghai area. The controls represented a 1% random sample of the defined living cohorts selected at the end of each of the 5 years of follow-up. Logistic regression showed an odds ratio of 2.77 (95% confidence interval: 1.52, 5.03) for drinking mutagenic downstream water from the river versus drinking nonmutagenic upstream water after controlling for possible confounders including age, disease history (hepatitis, cirrhosis, schistosomiasis, digestive tract ulcer), hazardous occupational history, pesticide exposure, lifestyle factors (cigarette smoking, tea intake, and alcohol intake), dietary habits (intake of pickled vegetables, maize, peanuts, and cured meat), education, poverty, urban environment, and water chlorination.

Three case-control studies of DNA repair in the general population were conducted with: i. 88 primary basal cell carcinoma (BCC) cases and 135 cancer-free controls, ii 304 study subjects including 57 arsenical cancer patients and 247 noncancerous controls in Taiwan and iii 41 breast cancer patients and 73 controls. The host reactivation assay was used to measure cellular DRC capacity with cryopreserved peripheral lymphocytes from both the cases and their controls. In study i. reduced repair of UV-induced DNA damage contributed to the risk of sunlight-induced BCC. A family history of BCC is a predictor of low DNA repair. Repair of UV damaged DNA declines at a rate of about 0.6 per annum in in non-cancerous controls. In addition, reduced DNA repair is more likely seen in young BCC cases, indicating that BCC is a premature aging disease of the skin. The persistence of photochemical damage because of reduced repair, results in point mutations in the p53 gene and allelic loss of the nevoid BCC (Gorlin’s syndrome) gene located on chromosome 9q. Xeroderma pigmentosum appears to be a valid paradigm for the role of DNA repair in BCC in the general population. An extension of these studies led to conclusions from Black Foot Disease (BDF) studies that DRC by itself is not a risk factor for arsenical skin cancer, but those individuals with low DRC,are at much greater risk when exposed to high levels of arsenic in their drinking water or when they are on poor diets. DRC, therefore, appears to be a susceptibility factor in this disease. Further DRC is consistently lower in breast cancer cases than in controls and appears to be a susceptibility factor in breast cancer and DRC in lymphocytes may be employed as a biomarker for human breast cancer risk.